He said that Bilawal raised his voice for Kashmiris and visited London to express his solidarity with them, The News International reported. Malik spoke to the media at his residence in Karachi, where he also urged the prime minister to order an inquiry into the matter.
Thousands attended the Million March in London on Sunday.
The rally started from Trafalgar Square and concluded at 10 Downing Street.
During the rally, protestors threw plastic bottles, shoes and cans at Bilawal Bhutto as soon as he took the stage at Trafalgar Square. The protestors shouted slogans against him and his father, Asif Ali Zardari.
They were angered because they thought that Bilawal wanted to use the platform to launch his political career.
Soon after Bilawal left the stage, people started tweeting with the hashtag, '#BhagBilloBhag'.